1. Norton’s Theorem. By: Engr.Irshad Raheem Memon
PRACTICAL # 07
Norton’s Theorem.
By: Engr.Irshad Raheem Memon

2. OBJECTIVE
Objective of this practical is to learn about Norton’s Theorem; and how this theorem is used to convert a complex resistive DC circuit into Norton equivalent circuit.

3. What is Norton’s Theorem
Norton’s theorem provides a method for simplifying any two terminal complex resistive DC circuit to an standard equivalent form. Norton’s equivalent circuit consists of an equivalent current source and a resistor in parallel

4. Norton equivalent circuit is shown in figure 01.

5. Description Continued…
Norton equivalent current is the close circuit (no load) current between two output terminals A & B in a circuit. Norton equivalent resistance is the total resistance appearing between two output terminals A & B in a given circuit with all sources replaced by their internal resistances.

6. Continued…
Norton’s equivalent circuit acts same in terms of output voltage and current as visualized in figure 02.

7. Steps for applying Norton’s theorem:
Step 01: Short the two terminals (remove any load) between which you want to find the Norton equivalent circuit
Step 02: Determine the current (IN) through the two shorted terminals
Step 03: Determine the resistance (RN) between the two open terminals with all sources replaced with their internal resistances.
Step 04: Connect IN and RN in parallel to produce the complete Norton equivalent circuit for the original circuit.
Step 05: Replace the load removed in Step 01 across the terminals of the Norton equivalent circuit. You can now calculate the load current and load voltage using only Ohm’s law. They have the same value as the load current and load voltage in original circuit.

8. Coming Towards Objective Now

9. REQUIRED APPARATUS Multism Software Resistors Bread board Multimeter
DC voltage source
Connecting wire etc

10. PROCEDURE
Realize the circuit on breadboard as shown in figure 01(a)Find out voltage across and current through terminals A & B in original circuit. Then convert this circuit into Norton equivalent circuit by following the steps of Norton’s theorem. IN and RN for original circuit can be found as given in figure 03.

11. STEP 01
Short the two terminals (remove any load) between which you want to find the Norton equivalent circuit

12. STEP 01 Circuit on MULTISM

13. STEP 02
Determine the current (IN) through the two shorted terminals

14. STEP 02 Circuit on Multism

15. STEP 03
Determine the resistance (RN) between the two open terminals with all sources replaced with their internal resistances.

16. STEP 03 Circuit on Multism

17. STEP 04
Connect IN and RN in parallel to produce the complete Norton equivalent circuit for the original circuit.

18. STEP 05
Replace the load removed in Step 01 across the terminals of the Norton equivalent circuit. You can now calculate the load current and load voltage using only Ohm’s law. They have the same value as the load current and load voltage in original circuit.
Now To Prove Results. We have to prove that Output Voltage and Current of Original Circuit must be Equal to Norton Output Voltage & Current

19. STEP 05 Circuit on Multism

20. Prove All Results Above Manually

21. Observation:-
Value of current through and voltage across terminals A & B in both original and Norton equivalent circuit is same.

22. ANY QUERY